1. Field of the Invention
This invention relates to an input device.
2. Description of the Related Art
As a conventional technique, an input device is known, the input device being configured to measure charging time in case that electrodes disposed in a capacitive touch panel (or capacitive touch screen) are charged, and discharging time in case that the electrodes are discharged so as to prevent misdetection (for example, refer to JP-A-2011-76515).
The input device includes a plurality of electrode pairs configured to be two-dimensionally arranged in a touch detection region, a selection circuit configured to sequentially select the plurality of electrode pairs respectively, a charging circuit configured to charge the electrode pair selected by the selection circuit, a charging time measurement circuit configured to measure a charging time from the time when the charging circuit starts to charge the electrode pair to the time when a predetermined upper threshold value is obtained, a discharging circuit configured to discharge the electrode pair charged, and a discharging time measurement circuit configured to measure a discharging time from the time when the discharging circuit starts to discharge the electrode pair charged to the predetermined upper threshold value to the time when a predetermined lower threshold value is obtained, so as to determine whether the touch of touch body to the touch region is detected or the detection is misdetection based on the ratio of the charging time to the discharging time.